5W-30 Makes Engine Quieter

Yes!

 

Yep.

 

The 1gr fe is rated for 0w-20 to 20w-50 so go ahead

 

A “20” weight oil is optiomal around 67* at “ambient”(that’s external” temperatures, and works well up to about 87*. Look at the oil temperature chart. I have seen posting that a “20” weight oil is good up to 104*.
I live in the Central Valley of CA, so I run 0W-40 during the Summer. According to the oil weight chart it is good to about 106*. Much better than a “20” weight oil if the ambient temperature goes up to 115*, which it has done for a time this summer.
The viscosities of “20” and “40” weight oils are similar, though not identical above 100*, with “40” weight oil being heavier.
If I lived in Death Valley, I’d be running 20-50 oil. My understanding that the only place where 0W-20 oil is speced for Toyota engines is North America.
Toyota says one can use a different weight oil different driving conditions (read that as “harsh”), but they don’t tell you what those conditions are.
If the ambient temperatures get down to 60*(current temperature is 53*), I certainly don’t need a “0W” oil. I worry more about the heat than the cold.

https://motorstate.com/oilviscosity-htm/

 

Zero W Forty year round in mine. 5000 mile intervals